Every 10 years, the Census Bureau takes a snapshot of life in our nation. We count our population while documenting living and working conditions. It's the largest and most–sophisticated national count in the world, and was mandated by our founders and enshrined in our Constitution.

While aggregate results are released immediately, the details we work so diligently to document — such as names and addresses — are kept strictly confidential for 72 years, when they are finally made public. The National Archives will release the details of the 1940 Census on April 2, 2012.

Taking the census is a daunting task that requires an enormous devotion of resources and years of planning — that much hasn't changed over the past 200 years. However, the process of completing the form was much simpler in 2010 — the form had only 10 questions and took less than 10 minutes to fill out.

With the release of the 1940 Census records, we are taking a look back at what has changed — and what hasn't — in how we conduct the decennial census.

The 1940 Census came at a momentous time in our nation's history — the country was emerging from the Great Depression and it was soon to enter World War II.

As preparations for Census Day ramped up in 1940, the Census Bureau partnered with newspapers and community organizations to let people know its workers would be coming to their doors.

With the nation much larger, the 2010 Census significantly built upon promotional efforts set in place during previous years to reach a wider and more–diverse nation.

Promotional efforts for both the 1940 and 2010 Censuses reflected the times. The 2010 Census relied heavily on a variety of communications tools — such as a road tour that crossed the nation — to inform communities about the importance of participating.

The 1940 Census form was longer than previous national counts and introduced a broad range of new questions. This was the first decennial census to ask a sample of the population an additional 16 questions.

Enumerators — more than 120,000 of them — interviewed residents and recorded their information in a portfolio–sized book.

The 1940 Census used 175,000 maps as guides for enumerators so they could personally visit every house, building, tent, cabin, hut or other place where a person might be living or staying.

In 2010, most households were given the opportunity to respond first by mail. Census forms were mailed to more than 120 million households.

The remaining households (plus the households that didn't mail back forms) were counted by 635,000 census workers walking neighborhoods throughout the United States — a practice that has taken place since the first census in 1790.

While many similarities exist between 1940 and 2010 in the door–to–door process, census workers from 1940 would have a hard time believing the advances in technology that enabled the tallying of the 2010 Census.

State–of–the–art technology in 1940 was a complicated process of transferring data from enumerators' census forms onto punch cards.

The 1940 Census utilized electronic tabulation equipment — similar to that first used in 1890 — to tabulate the millions of punch cards created from the forms.

The evolution of technology greatly reduced the time it took to complete the count. By 1940, the advancements in electronic tabulation permitted the processing of more data in less time, compared to the manual input of information that occurred for the 1880 Census.

By 2010, the Census Bureau employed computer technology. Optical scanners and computer software were used to "read" the handwritten questionnaires and convert the information into electronic data. The apportionment counts were released on Dec. 21, 2010.

Newspapers and radio shared the news of the final 1940 Census results. The Census Bureau reported that 132.2 million people lived in the United States.

Our nation grew considerably in the 70 years after 1940. The 2010 Census found 308.7 million people lived in the country. 2010 Census results are accessible online through interactive tools that provide detailed information on who we are as a nation. The individual records, though, are confidential until 2082... check back then for a complete picture.